In the season-opener, written by "Grimm" showrunners and co-creators David Greenwalt and Jim Kouf, and titled "Bad Teeth," we learned more about Ma Burkhardt (Mary Elizabeth Mastrantonio); Nick's boss, Captain-Not-What-He-Seems Renard (Sasha Roiz) and the history of Grimms, Wesen and that royal family that Renard's descended from; and we learned that Nick's girlfriend, Juliette (Bitsie Tulloch), is still in a Sleeping Beauty-style coma, and may lose her memory.

We also learned that, in launching its second season, "Grimm" isn't afraid to go deep into mythology territory, putting last season's Monster of the Week-style structure in the background, and assuming viewers have been keeping up. Will the mythology emphasis continue as the season goes forward? We'll see, but I wouldn't be at all surprised, since the show's fans have lobbied for more backstory and exploration of the world of Grimms, Wesen and that shadowy Renard royal family business.

Let's recap!

The quote that opens the episode -- "The blood-dimmed tide is loosed, and everywhere the ceremony of innocence is drowned" -- isn't from a Grimm fairy tale, it's from W.B. Yeats' poem, "The Second Coming." As we may recall from high school English, this is the poem famous for its apocalyptic imagery. Remember the ending? "And what rough beast, its hour come round at last,/Slouches towards Bethlehem to be born?" (Extra credit for recognizing the title of Joan Didion's essay collection.)

Perhaps as another treat for English majors, the pre-credit sequence features a luckless security guy, checking out a ship arriving in the Portland harbor, who identifies himself as "Yeats." The poor guy quickly meets a bloody fate at the hands of the creature possessing the "bad teeth" of the title (his Wesen name is a French translation, "Mauvais Dentes"). This critter is a sort of saber-toothed tiger, and he's bad news. Naturally, he -- it? -- is after Nick.

But after these opening non-pleasantries, we're back where the Season 1 finale left off. That is, Nick's at home, fighting Kimura, the bad guy who came to Portland to commit mayhem, and is now on the hunt for the mysterious, power-bestowing Coins of Zakynthos. There's much combat -- messing up Nick's house yet again -- and then the Woman in Black -- aka, Ma Burkhardt -- appears, whomping Kimura. Nick holds a gun on her, as she says, "Nick. Nicky, it's me." And he says, "Mom?"

Nothing like a heart-tugging mother-and-child reunion, is there? Ma Burkhardt explains that she's not actually dead -- obviously -- despite Nick believing she was for the past 18 years. He had been told his mother and father died in a car accident, but she wasn't in the car, she explains. Instead, a friend was in the car, and after the accident -- which was no accident, as bad guys were intending to kill Nick's parents -- the bad guys cut off the friend's head, thinking she was a Grimm. Kimura was one of the bad guys, and Ma Burkhardt wants to get the download from Kimura about who betrayed them. But Portland police have since shown up and arrested Kimura.

Nick, not surprisingly, is feeling a bit conflicted about the sudden reappearance of Dear Old Mom. "Is my Dad gonna come back from the dead now?" he asks. Ma Burkhardt assures him, no, Dad's still dead. Oh. And, not missing the fact that Nick's understandably angry about her disappearing act, Ma says, "It was safer for you if I was dead."

Interrupting these not-so-tender moments is the arrival of Monroe (Silas Weir Mitchell) and Rosalee (Bree Turner), who have been working on figuring out how Magique the cat scratched Juliette into a coma. Their first meeting with Ma Burkhardt doesn't go so well; they creature out at the sight of her, and she leaps to attack, grabbing Monroe with malice aforethought. Nick calls her off.

Ma isn't thrilled at the news that her Grimm son is friends with a couple of Wesen, and when Monroe and Bree tell Nick that Juliette's in real danger, Ma says, "Who's Juliette?"

"Oh wow," says Monroe. "So you two really haven't caught up in any significant way, I guess." Understatement, thy name is Monroe.

They explain that Juliette is in danger of suffering total memory loss unless she's awakened from that Sleeping Beauty-style big sleep. Oh, and by he way, Monroe tells Nick, "Your mother scares the crap out of me, man," adding, "Family reunions can be brutal. Our last one, we lost two cousins -- and a sheepdog." How I yearn to know more about those Monroe clan get-togethers.

After this fast start, we wade into some deep waters of exposition, explanation and revelation. To review:

* Ma gives Nick the lowdown on the royal families (which we know Renard is descended from) that date back to ages ago, who are responsible for much of the turmoil in the world. She also tells him that, according to legend, there are seven keys, forged by the knights who fought for the fourth Crusade, ans there are ancient maps that tell where the knights hid the wealth they took from Constantinople after they sacked and burned it. "Those knights are our ancestors," she says. They fought for the royals, as did the Wesen. But the royals needed Grimms to control the Wesen, "as they do now," says Ma. Plus, there's the McGuffin, as Hitchcock used to call the plot element that drives everything -- turns out there's some secret, well, thing, that the royals need so they can control the world. This powerful thing has been hidden, and Ma doesn't know what it is. But more to the point, Nick's in danger, because the royals know he has one of the keys, and "they want you dead." But he hasn't shown it to anyone, he says. "There must be somebody in Portland who knows" he has it, she says.

* So about those coins: Ma still wants them, and as she tells Nick this, there's something in her manner that makes me wonder whether she's got some private agenda that goes beyond getting the coins to safety for the good of one and all. Does Ma have a bit of hunger for the power the coins can provide? Just asking.

* After his initial wariness and resentment for being deceived, Nick's attitude toward ol' Ma warms up, and he chokes up as he tells her he wishes he hadn't been left without her for all these years. They embrace, and Ma seems choked up, too. Not that she's the most maternal type, but she does tidy up Nick's trashed house and attempts to make him breakfast. But Mother of the Year? Still not so much.

* Meanwhile, Renard has his own interests. He visits the chilly mother of Adalind -- who's so witchy she makes Ma Burkhardt look as nurturing as June Cleaver -- to try and get info on how to bring Juliette back from the coma brink. Why? He doesn't want anything to happen to Juliette, Renard says, "Because she ties (Nick) here to Portland, to me." If Juliette dies, Nick could leave the force and leave Portland. And Renard has put too much time and effort into Nick to allow that to happen. What time and effort? You mean all that glowering and hovering at Portland police headquarters? "A Grimm on his own is dangerous for all of us," Renard tells Adalind's mother.

* Also meanwhile, Hank (Russell Hornsby) is still utterly freaked out and paranoid by having seen Wesen in action, with no explanation, and nobody he can confide in. He's alone at his place, holding a gun and gobbling down some pills. That can't be good. But he at least does manage to get out of the house to accompany Nick on an investigation into the murders on the ship, caused by that French-accented, bad-toothed creature-villain, sent to kill Nick.

* For a bit of mother-son bonding, Nick takes Ma Burkhardt for a visit to, of course, Aunt Marie's Trailer of Weird Weaponry and Expositional Library, down below the Fremont Bridge, in what still looks like the least-secure storage area in town. She gets nostalgic for the good old days, when Nick's grandfather took her out along with him on his Wesen hunts, and a forebear did some castrating with a knife that really looks like it means business. After they both get emotional, it's back to business, as Ma warns Nick about the bad-tooth Wesen, who's even worse than the Reapers who have already tried to kill Nick.

* As if Nick doesn't have enough to worry about, a couple of FBI agents butt into the case of the shipyard deaths (the female is Portland actress Katie O'Grady, who starred in James Westby's film, "Rid of Me"), and manage to get themselves held hostage (and worse) by bad-tooth Wesen guy, as a way to lure Nick to him for an ultimate showdown. Nick and Ma drive to the shipyard for the confrontation, and just when things are already stressful, Monroe calls Nick to tell him they've got to get to Juliette in the hospital to give her the potion to help her wake up. Nick's a little distracted, especially when what he thought was one of the three dead bodies turns out to be bad-teeth Wesen guy, who leaps up, and in full attack mode, comes at Nick, and...

TO BE CONTINUED.

Oh, man. A cliffhanger? What does this mean Could it be possible that Nick, our leading character, will be killed by that very bad kitty? No, of course not. But we do have to wait another week to find out what happens with Juliette, learn if Ma is really on the up and up with Nick, and maybe find out if those pills are helping Hank with his post-traumatic-Wesen-sighting syndrome.